introduction: the incidence of chromosomal abnormalities was investigated in untransfered embryos reuslted from in vitro fertilization (ivf) or intracytoplasmic sperm injection (icsi) procedures. materials and methods: a total of 238 embryos of varying morphology between the pronucleated stage and 8-cells were analysed. the cytogenetic method of dyban was used for chromosome preparation. embryo...

Embryonic mosaicism, defined as the presence of karyotypically distinct cell lines within an embryo, has been frequently reported with a high incidence in preimplantation embryos derived from IVF and is thought to be one of the major biological limitations for the routine application of PGD for aneuploidies (PGD-A). The incidence of mosaicism in preimplantation embryos is in fact reported to be...

Pou5f1/Oct4 is a key transcription factor for the induction of pluripotency and totipotency in preimplantation mouse embryos. In mice, loss or gain of function experiments have demonstrated an important role for Oct4 in preimplantation and developmental ability. In this study, using mouse preimplantation embryos as a model for the evaluation of Oct4 function, we constructed Oct4 overexpression ...

The serine protease tissue-plasminogen activator (t-PA) has previously been shown to be intracellular in mouse secondary oocytes and extracellular in fertilized eggs. Here we demonstrate that extracellular t-PA activity is bound to the surface of the fertilized egg. The level of t-PA activity associated with preimplantation mouse embryos decreases in the 2-cell stage embryo, then increases in 4...

Preimplantation embryos exposed to elevated temperatures have reduced developmental competence. The involvement of reactive oxygen species in these effects has been controversial. Here we tested hypotheses that (1) heat shock effects on development and apoptosis would be greater when embryos were cultured in a high oxygen environment (air; oxygen concentration1⁄4 20.95%, v/v) than in a low oxyg...

The purpose of the present study was to evaluate the effect of cryopreservation on 55 embryos which had one blastomere biopsied for preimplantation genetic diagnosis of aneuploidy before freezing. The thawing outcome was compared to that obtained in 94 embryos which derived from our conventional freezing programme in patients with comparable characteristics who were treated in the same period. ...

AIM We investigated whether recombinant mouse interleukin-6 (IL-6) affects the development of preimplantation embryos and induces the -signal transducers and activators of transcription (JAK-STAT) signaling pathway by binding IL-6 signal transducer (IL-6st) and regulating Fos and Jun gene expression, thereby accounting for the negative effect of superovulation on embryo development. METHODS W...